Managing three drinking water treatment facilities, multiple pump stations, more than 350 miles of pipelines, and a wastewater treatment facility is challenging even in normal conditions for a small city where agriculture is an economic driver and water demand can exceed 22 MGD.
It has been said that the unseen and untreated can break down any system — this phrase could not be more accurate than in the world of wastewater treatment when considering the infiltration of grit into a system. Infiltration happens in the collection system, whether it’s from living on the coast, aging infrastructure or just plain old build up over time.
A water utility in the Midwest USA uses Monochloramine treatment in their two surface water treatment plants to disinfect raw water and establish residual disinfectant prior to discharge to their distribution system.
The 34 MGD Otay Water Treatment Plant in San Diego, California serves a population of approximately 200,000. It is a conventional treatment plant that uses coagulation, flocculation, sedimentation, filtration and disinfection. The plant receives raw water from two different sources — imported water from the Colorado River and runoff water from three local reservoirs.
Turbidity measurement is both a nebulous, oft-misunderstood concept and the master link in a chain of events affecting U.S. EPA drinking water compliance. It can influence, or be influenced by, almost every other link in a water treatment process. Here is a quick overview of turbidity’s relationship to drinking water compliance standards and some tips for keeping a water treatment process in balance.
Nestled in the Finger Lakes region in upstate New York, the town of Owasco is a popular vacation spot. With about 4,000 residents, the town, along with the nearby community of Auburn, relies on Owasco Lake for its drinking water. In 2016, Owasco and Auburn detected algal toxins in their finished water for the first time. With the busy summer tourist season quickly approaching, GHD contacted Calgon Carbon.
Located in Northern Missouri, the city of Trenton and its more than 6,000 residents pride themselves on self‐sufficiency and pragmatic decision making. During the spring of 2012, the utility embarked on the design and construction of chemical feed system upgrades at the existing water plant that would help the city manage the need for new capacity, better control of trihalomethanes (THM’s) and improve operator safety by removing gaseous chlorine as a disinfectant.
The Lariana Depur wastewater treatment plant in Fino Mornasco, Italy, treats wastewater from multiple textile manufacturers in the Como region, known as the heart of the textile industry. Since 1994, ozone has been used effectively as a polisher to remove the dark blue-purple color — the result of the dyes used in the textile dyeing and printing process — from the water.
The history of commercial online transactions is riddled with horror stories about data security breaches. Think Equifax, Target, Yahoo, Uber, Sony PlayStation … the list goes on. How can a utility maximize the benefits advanced metering infrastructure (AMI) offers for more efficient data collection and management, without having to worry about seeing its name on the front page of tomorrow’s newspaper?
Changing climate and other environmental conditions are intensifying the frequency and severity of harmful algal blooms (HABs). Here are important guidelines to understanding HAB causes and impacts to potable water treatment plants — including dealing with the algal biomass, remnants of decaying algal cells, and especially the secondary metabolites that the algae produce, such as taste and odor compounds and toxins.
The QuEChERS (Quick-Easy-Cheap-Effective-Rugged-Safe) sample extraction method was developed for the determination of pesticide residues in agricultural commodities.
Before water can be used as a safe and reliable source for drinking water, it must be properly treated. Since water is a universal solvent, it comes in contact with several different pathogens, some of which are potentially lethal, and inactivation is accomplished through chemical disinfection and mechanical filtration treatment. This treatment consists of coarse filtration to remove large objects and pre-treatment which includes disinfection using chlorine or ozone
Electrodeionization (EDI) is widely used in many industrial water treatment systems throughout the world. In order to maximize the operating stability and life expectancy of an EDI system they were often designed with double pass RO using caustic injection pretreatment.
Electrical conductivity is the most convenient method for testing RO water quality and membrane performance. Pure water is actually a poor electrical conductor. The amount of ionized substances (salts, acids, or bases) dissolved in water determines its conductivity. Normally, the vast majority of the dissolved minerals in tap, surface or ground water
The Riviera Grise drains water from the Cul-de-Sac watershed, Haiti, which covers most of the rural areas along the flood plains and areas that extend into steep hillsides. It also covers urban areas of Port-Au-Prince, the capital city of Haiti.
The first step is to define the performance limiting factors in the application. For this application, most of the adsorber is used for MTBE adsorption in the ppb concentration range. Adsorption of BTEX, TBA, or humic acids or other total organic carbon (TOC) components are removed by the front end of the column.
Osmosis is the phenomenon of lower dissolved solids in water passing through a semi-permeable membrane into higher dissolved solids water until a near equilibrium is reached
The water municipality at a mid-size city in the Western region of the U.S. serving a population of about 180,000 people needed to address a chlorine disinfection system problem at one of its water treatment plants.
Ultrafiltration systems can be engineered and designed in several possible combinations based on the application and source water quality. There are different membrane materials, membrane shapes, flow types, and configurations.
An inherent vertical of the global specialty chemicals space, hypochlorite bleaches market has been observing remarkable popularity of late. With rising incidences of infectious illnesses on a global scale, the demand for disinfectants, bleaching, and sanitization products is likely to accelerate. Hypochlorite bleaches are popular disinfection products with the ability to terminate a vast array of disease-causing bacteria, fungi, viruses, and fungi, provided they are used with adequate precautionary measures and adhere to specific usage guidelines.
Which process should you choose for your application?
Many water utilities continue to evaluate the costs and benefits of investing in smart metering to reduce operational costs and help recover revenue from water losses. Smart metering can also provide customers with more granular consumption data to help them protect their property from water damage and better manage their water expenses.
Non-revenue water loss is a problem from coast to coast, but California has taken a lead and set an example — with resources from AWWA — by adopting and sharing best practices to help solve the issue.
The U.S. EPA regulates total trihalomethanes (TTHMs) to reduce risks from bladder cancer and other maladies, but studies suggest there are many other factors to consider.
In most developed countries, drinking water is regulated to ensure that it meets drinking water quality standards. In the U.S., the Environmental Protection Agency (EPA) administers these standards under the Safe Drinking Water Act (SDWA).
Drinking water considerations can be divided into three core areas of concern:
Drinking Water Sources
Source water access is imperative to human survival. Sources may include groundwater from aquifers, surface water from rivers and streams and seawater through a desalination process. Direct or indirect water reuse is also growing in popularity in communities with limited access to sources of traditional surface or groundwater.
Source water scarcity is a growing concern as populations grow and move to warmer, less aqueous climates; climatic changes take place and industrial and agricultural processes compete with the public’s need for water. The scarcity of water supply and water conservation are major focuses of the American Water Works Association.
Drinking Water Treatment
Drinking Water Treatment involves the removal of pathogens and other contaminants from source water in order to make it safe for humans to consume. Treatment of public drinking water is mandated by the Environmental Protection Agency (EPA) in the U.S. Common examples of contaminants that need to be treated and removed from water before it is considered potable are microorganisms, disinfectants, disinfection byproducts, inorganic chemicals, organic chemicals and radionuclides.
There are a variety of technologies and processes that can be used for contaminant removal and the removal of pathogens to decontaminate or treat water in a drinking water treatment plant before the clean water is pumped into the water distribution system for consumption.
The first stage in treating drinking water is often called pretreatment and involves screens to remove large debris and objects from the water supply. Aeration can also be used in the pretreatment phase. By mixing air and water, unwanted gases and minerals are removed and the water improves in color, taste and odor.
The second stage in the drinking water treatment process involves coagulation and flocculation. A coagulating agent is added to the water which causes suspended particles to stick together into clumps of material called floc. In sedimentation basins, the heavier floc separates from the water supply and sinks to form sludge, allowing the less turbid water to continue through the process.
During the filtration stage, smaller particles not removed by flocculation are removed from the treated water by running the water through a series of filters. Filter media can include sand, granulated carbon or manufactured membranes. Filtration using reverse osmosis membranes is a critical component of removing salt particles where desalination is being used to treat brackish water or seawater into drinking water.
Following filtration, the water is disinfected to kill or disable any microbes or viruses that could make the consumer sick. The most traditional disinfection method for treating drinking water uses chlorine or chloramines. However, new drinking water disinfection methods are constantly coming to market. Two disinfection methods that have been gaining traction use ozone and ultra-violet (UV) light to disinfect the water supply.
Drinking Water Distribution
Drinking water distribution involves the management of flow of the treated water to the consumer. By some estimates, up to 30% of treated water fails to reach the consumer. This water, often called non-revenue water, escapes from the distribution system through leaks in pipelines and joints, and in extreme cases through water main breaks.
A public water authority manages drinking water distribution through a network of pipes, pumps and valves and monitors that flow using flow, level and pressure measurement sensors and equipment.
Water meters and metering systems such as automatic meter reading (AMR) and advanced metering infrastructure (AMI) allows a water utility to assess a consumer’s water use and charge them for the correct amount of water they have consumed.